Deconditioning of musculoskeletal and cardiovascular systems occurs when there is a lack of gravitational load on the body during space flight. If conditioning exercise is not undertaken in such situations, substantial health problems will eventually ensue upon return to normal Earth gravity. Exercising in zero gravity poses many problems as most conventional exercise equipment and the exercises themselves are either dependent upon gravity or are limited to conditioning one set of muscles. What is needed for zero gravity exercise is a simple, self powered device which is not dependent upon gravity and which provides simultaneous, integrated musculoskeletal and cardiovascular stimulation. To effectively simulate exercise in Earth gravity, the device should impose pressure gradients across walls of blood vessels in the working muscle, especially in the lower body. Furthermore, externally-imposed pressure oscillations can facilitate blood flow to working muscle.
U.S. Pat. No. 5,133,339 to Whalen, et al. discloses an exercise method and apparatus utilizing differential air pressure. The apparatus includes a pressure chamber and an exercise device located therein. The chamber is not itself the exercise device and it requires an external power source to generate differential air pressure.
U.S. Pat. No. 3,836,141 relates to a chest exercising device in which a bellows mechanism is used to provide a resistance force against motion by the intake and expulsion of air. A valve is provided to control the resistance level. The device, disclosed in the '141 patent, is strictly external and does not effect pressure applied to the user's body.
U.S. Pat. No. 4,635,931 relates to a bellows like pneumatic exercise apparatus having attachments to secure the device to a bed post and a user with applications directed to leg and arm exercises.
U.S. Pat. No. 3,884,463 relates to a bellows type pneumatic exercise device which may be used for biceps, chest, back and leg exercises. The apparatus is held by the user.
U.S. Pat. No. 4,666,148 relates to an exercise device which is worn by the user to exercise face muscles. A mask having an inflatable liner is attached to the user's face. Once attached, the liner is inflated to provide resistance to facial motion. The unit is not sealed and the static pressure of the air bag liner is not negative pressure.
U.S. Pat. No. 4,772,016 relates to a pneumatic cylinder to provide resistance between two arms of a hinged exercise apparatus. A pressure restricter is manually adjustable to effect the resistance force.
U.S. Pat. No. 4,824,105 relates to an abdominal exerciser which is worn by the user having an air pressure chamber to provide bi-directional resistance to motion.
U.S. Pat. No. 4,830,366 relates to a compressible air bag used for exercising with various attachments to be secured to the body. Illustrated in this reference are examples of applications directed to arm and leg exercises.
None of these devices impose self-generated external pressure changes on the working muscle tissue. There is a need in the art for an integrated exercise device which provides both exercise for the user's muscles and external pressure oscillations on the user's body which can facilitate blood flow to the exercising muscles.